Furthermore, the Analytic Hierarchy Process (AHP) (Saaty 1980 , 1986 1992), an international acceptable quantitative tool, adopted in this study appears to be a flexible decision making tool for multiple-criterion problems such as the assessment of the potential zones of groundwater resources in rapidly urbanized area of SW-Nigeria.
Furthermore, the Analytic Hierarchy Process (AHP) (Saaty 1980 , 1986 1992), an international acceptable quantitative tool, adopted in this study appears to be a flexible decision-making tool for multiple-criterion problems such as the assessment of the potential zones of groundwater resources in rapidly urbanized area of Comoro watershed.
Algorithm 3.1 (Interactive Algorithm for Stochastic Bi-criteria Problems).
Additionally, we address bi-criteria problems to consider user costs as the second objective.
Moreover, a linear value function seems to predict choices for bi-criteria problems quite well.
PROMETHEE Method [24 28] is an outranking method used to solve multi-criteria problems, which are considered to be NP- complete [7].
Decision makers may find it hard to identify the best choice due to the lack of systematic methods to deal with multi-criteria problems since some critical factors are basically determined by subjective perceptions.
Methods: In this article, a consensus model for group decision-making (GDM), based on the analytic hierarchy process (AHP), is developed to gather group ideas and analyze the real estate investment environment under multi-criteria problems.
The optimal solutions found from the bi-criteria problems are shown to be close to the solution minimizing GHG emissions only, meaning that the emission minimizing policy can also minimize user costs.
Although the importance of using an appropriate problem representation has been clearly identified in the literature [19,25], and many visualization methods have been proposed for multi-criteria problems [30], this topic has not yet received sufficient attention [64].
Process optimisation is often a multi-criteria problem.
